Possible Clues:

• Mostly carefully search alien body found in space
• The firm encountered this from outer space
• This will arrive at the end of 24 across before tea from space
• Finish last on 'Jeopardy!'
• Christmas reindeer
• Blazing star
• Another of Santa's team
• Come to tea, and thereby hangs a tail
• Arrive from space before tea for 35 across
• Firm-faced - but the body's heavenly